1. Technical Field
The invention relates generally to a flexible endless conveyor belt. More particularly, the invention relates to a flexible endless conveyor belt having steel reinforcing cables. Specifically, the invention relates to a steel reinforced flexible endless conveyor belt having a fold-over capability in which the steel cables themselves are specifically tailored to increase the load-carrying capacity and improve the performance of the belt without interfering with its fold-over function.
2. Background Information
Various forms of belt conveyor systems are known in the art. The general purpose of a belt conveyor system is to move large quantities of materials from one location to another. Such materials are moved for a wide variety of reasons. One type of conveyor system transports materials through a sorting process whereby the materials are incrementally removed from the conveyor at points along its length such that all items are removed from the conveyor at its terminal end. Another type of conveyor system moves materials through a highly controlled process that alters the materials in some fashion. A third type of conveyor system is utilized solely to transport large amounts of material from one location to another.
Improvements in simple load-carrying conveyors have primarily been directed to increasing their load-carrying capacity and velocity. Other improvements have been directed to adapting such systems to carry materials up inclines and down declines such as a coal conveyor used in a subterranean mining location.
One improvement that has resulted in significantly increased carrying capacity and utility of such conveyors has been the creation of conveyor belts with fold-over capacity. In such systems, the belt is formed in a continuous loop with the additional feature that a series of rollers folds the outer edges of the belt over the medial section of the belt. In such systems, the materials are enclosed between the medial portion of the belt and the folded flaps. A second series of roller near the terminal end of the conveyor system returns the flaps to an unfolded position so that the bulk materials can be removed from the conveyor.
Fold-over belts enclose the bulk materials thereby protecting them from spillage and contamination. Such belts additionally allow the bulk materials to be carried over steeper inclines and declines than ordinary open-belt systems. Fold-over belts increase the load-carrying capacity and utility of a belt system while reducing the dust emissions inherent in belt transportation.
Fold-over belts are not, however, without problems. Such systems typically experience significant belt wear both in the flap portions and at the hinge areas, i.e., the areas between the flap portions and the medial portion that bend to create living hinges therebetween. In order to abate some of the wear at the hinge areas, a number of belts known in the art include one or more V-shaped channels formed in these areas on the load-carrying side of the belt to facilitate folding.
Other belts known in the art have included longitudinally oriented cables internally disposed within the belt that carry a portion of the overall belt tension. Such cables have typically been manufactured of steel. The increased tension carrying capacity of such cable-reinforced belts permits the belts to be operated at higher velocities and up and down steeper inclines and declines while correspondingly resulting in greater belt life because the cables carry much of the tensile load on the belts.
The addition of such steel cables, however, has not been without problems. While the addition of steel longitudinal cables in the medial and flap areas of the belt has resulted in improved load-carrying capacity and reduced wear in those areas, the hinge portions of the belt continue to be subject to increased wear. Thus a need exists for an improved fold-over belt having increased load-carrying capacity without the usual high level of wear in the hinged areas.
Moreover, steel cables oriented in the longitudinal direction provide little support in the transverse direction. An unevenly loaded conveyor belt having only longitudinal steel cables will deflect unevenly in the traverse plane in response to disparate loading. The need thus exists for an improved fold-over belt having improved resistance to the uneven deflection typically caused by uneven loading of the belt.
In light of the foregoing, an objective of the present invention is to provide an improved fold-over belt that experiences less wear and tear in the hinged areas thereof.
Another objective of the present invention is to provide an improved fold-over belt having longitudinal cables therein.
Another objective of the present invention is to provide an improved fold-over belt having transverse cables.
Another objective of the present invention is to provide an improved fold-over belt having a reduced tendency to deflect unevenly in response to uneven loading.
Another objective of the invention is to provide an improved fold-over belt to having reduced strain in the hinged areas.
Another objective is to provide a belt which is of simple construction that achieves the stated objectives in a simple, effective, and inexpensive manner, and that solves problems and satisfies needs existing in the art.
These and other objectives and advantages of the invention are obtained by a flexible endless conveyor belt, the general nature of which may be stated as including a top layer defining a load-carrying surface, a bottom layer defining a driven surface, the driven surface being substantially parallel with the load-carrying surface, the driven surface adapted to being driven and supported by various rollers, the top layer and the bottom layer terminating at a common first edge and a common second edge such that the load-carrying surface, the driven surface, the first edge, and the second edge define a rectangular cross-section of substantially greater width than thickness, a pair of longitudinally-oriented hinged areas, the hinged areas defining a medial portion therebetween and further defining a first flap extending between one of the hinged areas and the first edge and a second flap extending between the other of the hinged areas and the second edge, a plurality of support cables, the support cables longitudinally oriented and disposed within the medial portion and the first and second flaps, and the belt being constructed of a flexible resilient elastomeric material.